Streptococcus pneumoniae HtrA is a dynamic and monomeric virulence factor capable of forming larger oligomeric complexes.

ABSTRACT: High-temperature requirement A (HtrA) proteases are a conserved family of serine proteases central to protein quality control and bacterial virulence. While Gram-negative and human HtrAs are structurally well studied, Gram-positive homologs remain essentially uncharacterized. Here, we present the first integrated structural and mechanistic analysis of a Gram-positive HtrA, from Streptococcus pneumoniae, a virulence factor essential for adhesion and infection in vivo. Proteomic profiling of an htrA knockout and cleavage assays demonstrate that S. pneumoniae HtrA is required for protein quality control, with the PDZ domain mediating substrate recognition. Biochemically, S. pneumoniae HtrA exists exclusively as a monomer in solution, a striking divergence from canonical trimeric HtrAs that we

SUBMITTER: Lee E 

PROVIDER: S-EPMC12745498 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature